Congenital corneal anesthesia: a series of four case reports.

PURPOSE: Discussion of four cases of congenital corneal anesthesia with varied systemic associations and modes of presentation. Classification and systemic associations of congenital corneal anesthesia along with the importance of multi-specialty evaluation of such patients.
METHODS: Clinical examination of all four cases and corneal sensation assessment with Cochet-Bonnet esthesiometer. Thorough systemic examination and investigations including serum bio-chemical analysis, roentgenography, ultrasonography, nerve conduction studies, and CT scan of the patients to identify systemic associations.
RESULTS: All four patients proved to have bilateral congenital corneal anesthesia with Cochet-Bonnet esthesiometry confirming corneal anesthesia. Systemic examination revealed associated congenital mesenchymal anomalies in the first case. The second case had generalized reduction in pain sensitivity confirmed by nerve conduction studies. The third case was an isolated bilateral congenital corneal anesthesia, while the fourth was a case of congenital trigeminal nerve anesthesia involving all three divisions of both trigeminal nerves. Other causes of corneal anesthesia and self-inflicted corneal injuries were ruled out by clinical multi-specialty evaluation and appropriate investigations. Correct diagnosis and symptomatic treatment aided speedy relief of symptoms of all the patients.
CONCLUSION: Congenital corneal anesthesia is a rare condition and is often a diagnostic dilemma. Although more common conditions that cause corneal anesthesia can mislead the clinician, the congenital variant should be kept in mind in any case of intractable corneal ulceration in children. Early diagnosis, symptomatic treatment and measures to prevent further corneal damage will immensely help in retaining useful vision for the affected children.